Furnace and fuel-feeding device therefor.



C. J. GREENSTREET. FURNAGE AND FUEL PBEDING DEVICE THBREPoe.

APPLICATION FILBD-SEPT. 26,1912. 1 l L1 @@9250 Patented Sept;1 5,1914.

. 2 SHEETS-SHEET l.

C. J. GREENSTREET.

FURNACB AND FUELEBDING DEVICE THEREPOR.

APPLICATION FILED SEPT. 26, 1912.

Patented Sept. 15, 19141.

mmeee.

2 SHEETS-SHEET 2.

CHARLES .-r.l GREENSTREET, 'or WEBSTER anoyas, MIssoUnI.

FURNAGE AND FUEL-FEEDING :DEVICE THEREFOR.

Specication of Letters Patent.

rammen sept. is', rara.

Application led September 26, 1912. Serial No. 722,383.

T all whqmz't may concern: Be it known that I, CHAnLnsJ. GREEN- s'rnnn'r, 'a citizen of the United States, and a resident of the city of V'Vebster Groves, county of St. Louis, and State of Missouri, have invented a new and useful Improve.- ment in Furnaces and FueLFeeding Devices Therefor, of which the following is a specication. rIhis invention relates particularly to furnaces adapted4 to burn coal dust and small 'particles of coal which are Vtoo fine to be burned on a grate.

Heretofore efforts have been made to devise apparatus for utilizing coal dust or comminuted particles of coal as a fuel for furnaces; but such devices have been unsatisfactory except in extensive plants.

` The principal object of the present inventionis to provide an apparatus for burnj ing such fuel in small or moderate quantityand which will produce a. comparatively uniform heat whose intensity is subject t0 control.

The invention consists in a new and improved furnace and fuel feeding mechanism, and particularlyin the combinations and yarrangements of parts thereof hereinafter described and claimed.

form part of thisl specification, and wherein likeszsylnbols refer to like parts wherever theiyhoccunfrligure 1 is side elevation of an apparatus embodying my invention, with the furnace shown 'in vertical section; Fig. 2 is a plan of said apparatus; -3 is a central longitudinal section'of the fuel hopper and feeding device, showing 'an end of the furnace and', the fuel delivery pipe 40 and blower in side elevation; and Fig. 4 is a vertical section on the line 4 4 in Fig. 3, showing the blower. and air inlet.

in' elevation. A .Referring ,to Figs. `1 and of the draw- $5- ings,my. apparatus. comprises a furnace 1 provided with a fuel inlet opening 2 at one end, and stack 3 at the opposite end .through which the products of combustion leave the furnace. Within the furnace is al combustion chamber'4, which is long and narrow vand is provided with a bridge wall 5 atzabout midway of its length andv an arch wall 6 near the outlet into the stack. The top of the bridge Wall is higher than 5the top of the fuel inlet opening .Between l Inthe vaccompanyintg drawings, whichl the bridge Wall and fuel inlet 'opening is a door opening] in theside wall ofthe furnace, through which access may be had to the combustion chamber. A delivery pipe 8 connects the outlet ofa fan blower 9 60 with the fuel inlet opening 2, and over the air inlet to the blower is arranged a fuel hopper 10 and a motor driven mechanical device for regulating the feeding of powdered fuel intothe blower casing. 65

. Referring to Figs. 3 and 4, the fuel hopper l0 is mounted upon the top of a casing .11 containing the' mechanical Afeed regulating device. The bottom part of the hopper extends down into the casing, and isi'itted 70 with sliding bottom doors or gates 12, which -are adjustable horizontally to regulate the width of the' opening from the hopper into the casing 11, whereby the width vof the 1 downwardvmoving column of fuel is regulated. This ladjustment is effected by means of threaded rods 13 and thumb nuts 14 'held casing 11. VTwo endless chains 18, running. on sprocket wheels 19 fixed on shafts 2O and 21. mounted in the casing 11, pass through the openings 17 and over the bot- 85 tom of the hopper. The chains runs close -to the opposite side walls of the casing, and .are connected by metal angles or {iights 22 forming a horizontal conveyor or scraper moving across the bottom of the hopper vtoward the front opening 17.

A vertical slide A23 ,is adjustably mounted upon the front sidenf the hopper with its V:lower edgeprojec'ting down into the casing y11 .adjacent to the'front opening 17.V .A 95 'leather strip 24 along the lower edge of the :slide partly covers theopening and serves to limit the vertical width of the gapin the frontwall of the hopper at its bottom, thereby controlling the Athickness lof the l100 -carry a belt `3() from a pulley on the motor .driven shaft-31. The blower 9 is driven by a belt 32 from another 'pulley on the shaft 31. At the back end of the casing 11 is an opening 33 extending across 'it near its bot- 110` nuts 35.

ln the. bottom ofthe front of the casing 11 is an opening 36 and a passage '37 leads from this opening into the inlet opening 38 in the blower casing. The outer end of the passage 37 is provided with' an air inlet opening 39 closed by a damper 40. This damper may bev opened to allow air to enter the passage and mix with the air coming through the opening 33 and casing, and'thus regulate the-suction' in the casing. Within the blower casing is a centrifugal fan adapted to force the air and suspended coal particles entering its inlet through the delivery pipe 8 into the furnace. The blower delivery pipe 8 widens outin a horizontal 2"0l direction and contracts in' a vertical direcal tion on nearing its outlet at the fuel inlet opening in the furnace wall. Apslide valve il controlled by an adjusting screw 42 is y placed in the delivery pipe'near its outlet lso into the furnace.

i In the operation'of the device the fuel, which is in the form of powder ,or finely divided particles, is placed in the hopper and the blower and conveyer are set in motion.' The bottom doors of the hopper are adjusted until the openingbetween them is such that a thin column of -fuel can pass through onto the hopper bottom, where its downward movement is checked. The bottom portion of 'th-is, fuel column is picked up `s ,uctionof the blower and are carried through the blower and delivery pipe into the furnace. The sliding door 34 and damper Al0 are adjusted to create a swirling suction into the passage 37, with no back draft to blow coal dust into 'the atmosphere. 'lne slide 23 is adjusted until the quantity of coal dust passing beneath it is just sufficient to be completely consumed by the quantity of air passing into 4the blower. rlhe slide valve el is set to give sufcient velocity to the blast of air and vcoal particles to cause a strong blast against the bridge wall 5.

'lo start combustion in the furnace it is necessary to kindle a fire of wood or other suitable material vtherein'before turning on the blast of air and coal particles. A blast of alone may be used in starting the wood fire, and the fuel feeding device tl.iown into gear after a hot lire is thus started.

iai/'ing once put the furnace in operation,

in order tocontrol the temperature therein it.` is only necessary to vary the speed of the motor which drives. the blower and fuelfeeding mechanism, and by the use of a ther v mostat, the temperature within the furnace can be maintained substantially constant for- 3000 Fahrenheit *can be attained and main.v -1

tained substantially uniform by the use Aof my apparatus-` The .temperature of the furnace may be regulated alsoby simultane-4 ously adjusting the coal feed regulating slide 23 and the damper4 l0- inthe air:

inlet 39.

Having described one embodying my invention, I do no t desire to be -limited thereto, but I claim as my invention the following: 1. A feeding apparatus'for 'comminutcd' fuel comprising a hopper having an opening in its front wall adjacent to its bottom, a pair of doors arranged above. saidbottom and spaced therefrom, said' doors being .movable to vary the width ofthe opening between them, a series of flights arranged across said bottom below said/doors, means -for moving said flightstoward the front wall ofsaid hopper to control the passage.

form of apparatusn i of fuel through.l the opening therein', and means for causing'an air current to pass bein said wall.`

neath said bottom and across, the opening 2; A feeding apparatus for comminuted' fuel comprising a hopper having an opening in its frontwall adjacent to its bottom, a pair of doors arranged above said bottom and spaced therefrom, said doorsbeing moir-v able to vary the width of the opening be tween them, a series of Hights arranged` across said bottom below said ldoors, means for moving said flights toward the front wall of said hopper to control the passage of fuel through the opening therein, means for" causing an air current to passbeneath said bottom and across the opening in said wall,

a passage having one end opening into the air and the other end terminating in a delivery duct, and means for drawing air through said passage and commingling it with said air current.

3. ln an apparatus for burning comminuted fuel', a furnace having an elongated combustion chamber, one end of said come,l bustion chamberhaving an outlet for ythe' products of combustion "and the other end thereof having a fuel inlet duct, and. means forforcing a constant stream of air and comming-led.' particles of coal dust through said inlet duct, said means-comprising a blower, an air inlet duct for said blower, and mechanical. means for feeding fuel continuously into said blower inlet duct, said being located above said blower vinlet duct,`

fuel feeding i'neas comprising a'hopper having an adjustable bottom opening,b and axed bottom below said adjustable bottom opening, said hopper having an end opening above said fixed bottom, said end opening and means movable across said fixed-bottom ered to said furnace.

for transferring said fuel through said end openingA into' said blower inlet ductv in a lthin sheet.

4. An apparatus for feeding and burning comminuted fuel comprising a combustion chamber having a fuel inlet opening and an outlet opening for the4 products of combustion, a fire wall in said combustion chamber between said inlet and outlet openings, a

said lelongated opening and discharging into,

the inlet of said blower whereby said fuel is uniformly -commingled with air and 5. An apparatus for feeding and burning comminuted fuel comprising a combustion' chamber having a fuel inlet opening, a blower having a delivery pipe communicating with said inlet opening, and means for a feeding fuel in a substantially uniform sheet into said blower,'.said means comprising a hopper for said fuel having a fixed bottom and an adjustable gate spaced above it, said hopper having an elongated opening eXtending across one end thereof below said gate,A

and a passage for air currents crossing said elongated opening and discharging into the inlet ofv said blower, said passage having an adjustable air inlet opening. v

6. An apparatus for feeding and burning .comminuted fuel comprising ya combustion chamber having a fuel inlet opening and an` outlet opening for Ithe products of combustion, a blower having an intake duct and a delivery pipe communicating with said inlet opening, and ,means for feeding fuel in a substantially uniform stream into said blower intake duct, said means comprising a hopper for said fuel having an elongated opening extending across its bottom at one end thereof, a casing beneath said hopper, an endless conveyer having flights arranged to move the fuel endwise of said bottom and through said opening into said casing, means for actuating said conveyer, a slide extendingfrom above said elongated open' ing into said' casing, an opening in said casing communicating with said blower 1nl blower.

deliv! take duct, and 'means in said duct controlling the velocity of the air entering said casing.y I j j. 7. An apparatus for feeding and burning l comminuted fuel comprising a combustion 7o. chamber having a fuelinlet opening and an outlet opening for the productsof combustion, a blower having ba delivery pipe communicating with said inlet opening, 'and means for feedingv fuel in a substantially uniform sheet into said blower, said means comprising a hopper for said fuel having an elongated opening extending across itsbottom at one end thereof,.an endless conveyer having fli hts arranged to move the fuel endwise of said bottom and through said opening, means for actuating said conveyer, a casingbelow said hopper bottom having an adjustable opening at the end remote from said hopper bottom opening, a slide extending into the upper side of said casing and terminating above said hopper bottom A opening, an eddy chamber in said casing below said hopper bottom opening, and a discharge chute from said' casing into said 90 8. In an apparatus for burning comminuted fuel, a furnace having an elongated combustion chamber, one `end of said combustion' chamber having an outlet for the 95 .products of combustion and the other epd thereof having a fuel inlet duct, and means for forcing a constant stream of air and commingled particles offcoal dust through said inlet duct, said means comprising a blower and mechanical means for feeding fuel continuously into the air inlet of said blower,

^ said fuel feeding means comprising a hopper having a bottom opening, stationary means below said bottom Openin for checking the fall of fuel through sai bottom opening, said hopper having an end wall provided with an end opening below said bottom` opening, means for adjusting the width of said end opening',-an inlet duct for said 110 blower under said end opening, and movable means for transferring said fuel through said end opening into said blower inlet duct.

9.A feed1ng apparatus for comminuted fuelcomprising a fuel receptacle having a -bottom opening extending lengthwisethereof, a wide 'flat bottom below said opening, said receptacle having an end wall terminating above said bottom and having an elon'- gated opening of equal width to said bottom opening parallel to said bottom, laterally movable closures for said bottom opening whereby the width of the fuel passage may be adj usted, and the greater part of the fuel supported above said bottom, a series of iiights longer than the width of said fuel passage arranged .across said lbottom with their ends beneath said closures, means for moving said flights lengthwise of said bottom whereby the fuel thereon is carried belonge? the Width of seid fue passage er'ang'ed aovoss seid bottom Wlth then ends 15 y beneath seid oosues, and means for moving said gbto lengthwise of sai bo tom Whereby the fuel thereon 'is earned beneath sani end Wa Wxthout becommg compacted.

Signed at St. Louis, lViissoor,-this 20th 20'- day-O September, 1912. v v

CHARLES l. GREENSTREET.

-tbnesseen A. M. HoLooMm, A. P. KESSLING. 

